I think you're twisting my point. Of course it's not a cumulative point system but the Blights aren't forgotten. In fact they can be held up as great examples, during the time of the Inquisition, as to why mages deserve acceptance. 1000 years ago nobody would have ever thought that mages deserve acceptance, now by the age of Inquisition, thanks to things like the mage contribution to the Blights etc., people like Leliana do support the mages and can hold up these incidents as reasons for why mages should be accepted. How do you think people came to accept mages? It was because the mages have built a case through these events. Sure the Blights might not create any substantial change during the time, but it's always going to be part of history and it's always going to be an example that the mages can hold up and say "we deserve to be accepted". People look at that history, and the mages that they come into contact with, and think "why don't people accept mages? They've done so much to help". That's why this change has long been coming. And that is what Leliana is pushing for. Sure it's controversial. But the case is there.
One must take the mages' rejection in both Asunder and Inquisition as simple backlash after Anders and the Conclave. But by allowing the mages to help you draw a distinction between Tevinters, like Corypheus and the Venatori, and Southern mages like the rebels aiding the Inquisition.
As I said before, this did not happen overnight. It took a thousand years of good deeds by the mages to atone for the "sins" of the Ancient Tevinter Imperium and even then it's still a precarious and conflicted thing. The case, I can't stress this analogy enough, is there.
Edit: The other point that I think is fundamental here, but may have gotten lost in the wall of text, is the idea that mages now have sympathisers and supporters like Leliana and Mother Giselle. 1000 years ago when the Tevinter Imperium fell do you think anybody felt that way about mages? I doubt it. But by the time of Inquisition the good deeds of the mages have shown the world, that perhaps mages aren't that bad. So by this time there are actually people willing to push for mage acceptance aside from mages themselves. In that chaotic time after the Circles were formed I doubt anybody was willing to do so. 1000 years of change my friend.
I understand that you saw an epilogue where mages were accepted and then attempted to construct a narrative where this makes sense but, ultimately, such a narrative goes against everything else the series has presented and thus your point does not have much ground to stand on.
Have we ever seen a single peasant saying something to the effect of "Boy, it's not right those mages are locked up when they helped us with the Second Blight all those centuries ago."? In fact, considering how most people can't even read, I doubt people know when the Second Blight happened.
In fact, have we ever seen a common man saying that mages should be free?
On the other hand, there are dozens of cases of common people and nobles and kings and priests lashing out against mages.
Therefore, a narrative where mages have been slowly gained acceptance over hundreds lacks strength because we never see any hint that that is happening.
It would have made sense in Kirkwall because there, we heard during the course of the three acts that people were turning against the Templars and the city was being divided. But neither DAI nor Asunder nor DAO ever gave any indication that was happening elsewhere.
Certainly, there are sympathizers. Mostly the wealthy who can afford to wonder just how far the world is and Leliana can certainly make a declaration the mages will be free but ultimately, the population at large has to accept that that is a reality.
And, as I said before, we are never given any indication people are more accepting of mages nowadays.